Abaixo está uma instrução que descreve uma tarefa de geração de SQL, combinada com uma entrada que fornece mais contexto sobre os esquemas de tabela disponíveis. Escreva o código SQL que responda adequadamente à solicitação
 ###Instrução: Qual nível tem uma Liga disputada pela Northern Premier League Premier Division, e uma Temporada de 2011-12?
 ###Tabelas: CREATE TABLE season_3_1996–1997 (season_3_1996–1997_id AUTO_INCREMENT PRIMARY KEY, Series # INT, Season # INT, Title VARCHAR, Directed by VARCHAR, Original air date VARCHAR, Production code VARCHAR) CREATE TABLE house_of_habsburg_1653–1722 (house_of_habsburg_1653–1722_id AUTO_INCREMENT PRIMARY KEY, Name VARCHAR, Birth VARCHAR, Marriage VARCHAR, Became Duchess VARCHAR, Ceased to be Duchess VARCHAR, Death VARCHAR, Spouse VARCHAR) CREATE TABLE league_and_cup_history (league_and_cup_history_id AUTO_INCREMENT PRIMARY KEY, Season VARCHAR, LeagueContested VARCHAR, Level INT, LeaguePosition VARCHAR, Avg.Home Attendance 1 VARCHAR, FA Cup VARCHAR, FA Trophy VARCHAR, Leading scorer 1 VARCHAR) CREATE TABLE kazakhstan (kazakhstan_id AUTO_INCREMENT PRIMARY KEY, Name VARCHAR, Pos. VARCHAR, Height VARCHAR, Weight VARCHAR, Date of Birth VARCHAR, Club VARCHAR) CREATE TABLE operation (operation_id AUTO_INCREMENT PRIMARY KEY, Maximum Ceiling Temperature VARCHAR, Temperature Rating VARCHAR, Temperature Classification VARCHAR, Color Code (with Fusible Link) VARCHAR, Glass Bulb Color VARCHAR)  
SELECT AVG Level FROM league_and_cup_history WHERE LeagueContested = northern premier league premier division AND Season = 2011–12